Co-gasification of biomass blends: Performance evaluation in circulating fluidized bed gasifier

摘要

An important aspect of the commercialization of biomass gasifiers is feedstock flexibility. The present study has dealt with performance assessment of a circulating fluidized bed gasifier (50 kW_(th)) with binary blends of three biomasses, sawdust (SD), rice husk (RH) and bamboo dust (BD), as feedstock. The performance of gasification was assessed in respect of the specific yield of producer gas, its LHV, and tar content in addition to gasification efficiencies. Experiments were conducted with varying equivalence ratio (ER) from 0.19 to 0.35, and temperatures of 800°—900 ℃. The blending of biomasses resulted in the enhancement of gasification performance due to synergistic effects. Minerals in the ash of RH catalyzed char and tar conversion leading to higher efficiencies. At ER = 0.35, maximum CGE = 62% and CCE = 98% were obtained for RH + BD blend. With increasing temperature, H_2, CO content and net yield of producer gas increased with concurrent decreasing in tar. The highest LHV of producer gas (5.05 MJ/Nm3) was obtained for the RH + BD blend at ER = 0.19 and 800 ℃. Maximum gas yield (1.72 Nm~3/kg dry biomass) and minimum tar content (2.01 g/kg dry biomass) were obtained for SD + BD and RH 4- BD blends, respectively, at 800 ℃ and ER = 0.35.